Saw-mill head-block



(No Model.)

T. S. WILKIN.

SAW MILL BLAD BLOCK.

No. 311,701. Patented Feb. 3, 1885.

L W71 asses.- E Zwaar/21,071-

Darren rares armer FFICE@ 1 THEODORE S. VVILKIN, OF MILWAUKEE, VISCONSIN.

SAW-MILL HEAD-BLOCK.

SPECIFICATION forming part of Letters Patent No. 311,701, dated February 3, 18185,

Application filed OctolnrH, 1844. (Nomode'.)

and it consists in novel devices for adjusting the knee upon and independently ot' the headhlock for taper sawing or like purposes, and securing the knee at the required point. l

In the accompanying drawings, Figure I is a side elevation, partly broken away to show the operating parts, Fig. 2, a transverse sec# tion on the line x x of Fig. 4l; Figs. 3 and 4,

like views showing a modified form ot' shitting or adjusting mechanism; Fig. 5, a detail view.

I may here remark that this lever mechas ism for moving the knee upon and independl ently ot the head-block is not ot' itself new in either ofthe forms shown; but the two forms more commonly in use are illustrated for the purpose of showing the adaptation ot' my improvements to different shifting mechanism'.

A indicates a head-block supported upon sills B B of the usual truck, which truck is ordinarily provided with two or with three head-blocks and theirattendant parts.

C indicates a sliding knee` having lateral ribs or flanges a, which travel in grooves b in the head-block and guide the knee in its movements back and forth.

Within the lower part of the k nee C, and projecting below the same, is a rack-bar, D, having grooves c in its sides to tit the guiding ribs or ways d of the knee, (shown in Fig. 2,) said bar lbeing provided with teeth e from end to end a suitable distance on its upper side.

causes the rack and the knee to be moved jointly forward or backward, as may be re quired. Vhen, however, it becomes necessary to saw logs or beams tapering, one or more of the knees ot' the carriage requires to be moved forward orbackward of the line of a given knee, which ordinarily is not made independently adjustable. rI`his adjustment is eti'ected by a lever, G, pivoted in the knee and connected by a link, H, with the rack-bar D, as in Fig. l, or fashioned into a toothed segment atits lower end, and made to mesh with teeth on the upper face of said rack-bar, as in Fig. 3, both pans being now in common use.

To hold the lever G in the position to which it may be moved, and thereby to lock the knee and the rack-har iirmly together and prevent independent or relative movement, it has hitherto been customary to prov-ide a notched or recessed arc, and to furnish the lever with a locking-bolt to enter the notches or recesses thereol when not held therefrom. Such arrangement adds to the cost ot' construction and occupies space which it is desirable to leave clear. I therefore provide the locking device or mechanism illustrated in Figs. l and 3, consisting cfa toothed rack-bar, I, pivoted in the knee and adapted to engage with the teethf. So long as the latch-bar I remains in engagement with rack-bar D the knee and rack-bar will be firmly locked together; but it' the latch-bar be raised out of engagement the knee may be moved independently ofthe rack,which latter, being in engagement with pinion E, cannot move except as the pinion is rotated. The latch-bar is arranged to fall by gravity and engage with the teeth f of the rack-bar, and to render its action quicker and more certain I add a spring, J, which presses down upon the latch-bar and prevents acci-A dental disengagement.

I preferably employ a spi ral spring,its lower end encircling a stud, g, on the latch-bar, and its upper end similarly encircling a stud, h., on the threaded plug K.which is screwed into an opening in the upper side of` the knee C, and terrified with a polygonal head to receive a wrench or like tool, by which the plug may be turned up or down for removal or insertion or to vary the pressure of the spring. This arrangement permits a new spring to be ap plied or the old one to be adjusted at any time without dismounting the knee.

ATo raisethe latch-bar when necessary, I provide the lever G with a` pivoted L- shaped hand-piece, L, from the angle of which a rod, M, is carried down and attached to a laterally-projecting arm, t', of the latch-loarI,which IOO eXtends outward through a slot lor opening',j,

'in the side of the knee C, as shown in Figs. 2

and 4.

When it is desired to move the knee independently of the rack-bar, it is only necessary to grasp the upper end of lever G and the handpiece or small lever L, which will both be grasped with one hand, move the lever G forward or backward in the direction required and to the proper distance, and then release the hold, whereupon the latch-bar Iwill drop into engagement with the' teethf of rack-bar D, thereby locking the parts in proper relative positions.

It will be seen that the above arrangement alone permits no independent adjustment of knee t'or any distance less than one tooth f,- hence itis important that some other means 'be provided for finer adjustments to secure perfect alignment of the knees of a saw-mill carriage. For this purpose I provide for the latch-bar I an eccentric pivot, Ic, Figs. 1, 3,

and 5, which has a throw or eecentrieity equal tothe space of one ofthe teethf, and which. being rotated in its bearings in the knee, will move the latter independently of the rack-bar D any distance desired up to the limit of its throw.

The eccentric pivotKis provided at one end with a clamping or binding nut, Z, or may be otherwise held against rotation after proper adjustment, and it is formed with a polygonal head, m, to permit it to be readily turned by a wrench or. like tool. TheleverG is formed with a horizontal cylindrical port-ion, which is journaled in the knee, as shown, the upright arm ofthe lever, as also rod M, being at the side of the knee, as shown in Figs. Zand 4, so as to avoid any opening in the upper side of the knee, through which chips or sawdust might enter and clog the teeth of the rack-bar and latch.

It is obvious that the lateh-barmay be pivoted to the rackbar and its free end arranged to engage with the sliding knee, such arrangement being merely a reverse of that shown and described.

Having thus described my invention, what I claim isl. In combination with ahead-block, a rackbar movable in relation to said head-block, a knee adjustable independently ofthe rackbar, a latch for locking the knee and rack-bar together, said latch being pivoted to one of said parts and adapted to engage with the other. and a shifting-lever fulcrumed in the knee and connected with the rack-bar, substantiallyias shown and described.

2. The combination, substantially as herein described and shown, of a head-block, a setting rack-barprovided with teeth on opposite sides, a setting-pinion meshing with one set of said teeth, a knee adjustable independently of the rack-bar, and a toothed latchbar pivoted to the knee, adapted to engage with the second set of teeth thereof and to lock the knee to the rack and prevent independent movement ofthe knee or rack in either direction. A Y

3. The combination of a head-block, a setting rack-bar provided with teeth on its up per and lower sides, a setting-pinion meshing with the teeth of one side, a knee adjustable independently of the rack-bar, a latch-bar pivoted to the knee and adapted to engage with the teeth of the other side of the rackbar, and ashifting-lever fulcrumed in the knee and connected with the rack-bar, substantially as described and shown.

4. The combination o f a head-block, a setting rack-bar/provided with teethion opposite faces, a settingpinion meshing with the teeth ofone face, a knee adjustable independently of the rack-bar. a latch-bar pivoted to the knee and adapted to engage with the second set of teeth of the rack, a shiftinglever fulcrumed in the knee and connected with the 5 and a hand-piece pivoted to the shifting-lever, connected with and serving to lift the latchbar out of engagement with the rack.

5. The combination of a head-block, a setting rack-bar,` a knee adjustable,independently of the rack-bar, a latchfba-r adapted to lock the rack-bar and knee together and prevent independent movement in any direction, andaJ spring bearing upon said latch and serving to hold it in engagement with the rack, substantially as set forth.

6. The combination of a head block, a rackbar movable in relation thereto, a knee adA j ustable independently ofthe rack-bar, a latchbar adapted to lock the knee and rack-bar together, said latchbar being pivoted to one of said parts and adapted to. engage with the other, a spring bearing upon said latch-bar.,

, rack-bar,substantially as described and show n,

and an adjustable screw-plug bearing upon the spring, substantially as described and shown.

7. The combination of a head-block, arackbar, and a knee adjustable independently of the rack-bar, a latch adapted to lock the knee and rack-bar together, and an adjustablepivot for the latch, substantially as and for the purpose set forth.

8. |The combination of a head-block, A, a sliding rack, D, an independently-adjustable knee, C, a latch-bar, I, adapted to lock the- IIO knee and rack-bar together, said latch-bar bel ing attached to one of said parts and adapted to engage with the other, and an eccentric pivot,-c, for said latch-bar, provided with/*aff clamping or binding device, substantially as shown and described.

' THEoDoRE s. wiLKiN.

Vitnesses:

M. C. KRAUsE, FRED. A. LARKIN. 

